An Iodabenzene Story

作者：Rawashdeh Abdel Monem^*; Parambil Priyakumari Chakkingal; Zeng Tao; Hoffmann Roald^*

来源：Journal of the American Chemical Society, 2017, 139(20): 7124-7129.

DOI：10.1021/jacs.7b03388

We call iodabenzene a cyclic (CH)SI molecule. A planar iodabenzene would have 8 pi electrons, a situation best avoided by an out-of-plane distortion to a bird-like geometry. The electronic structure and charge distribution of this molecule resemble those of Meisenheimer complexes, derivatives of (CH)(5)CH2-. A similar substitution strategy, of pi-acceptors in ortho and para positions, works in both cases to planarize and stabilize such derivatives. Some 40 kcal/mol (73 kcal/mol for the unsubstituted case) below the bird, a classical 5-iodocyclopentadiene structure awaits, reached through a bicyclic transition state. The calculated activation barrier for the highly exothermic reaction to a classical Lewis structure nevertheless make us optimistic about the chances of detecting and even isolating the bird isomer.

• 出版日期2017-5-24